bought the filter bag to have all the filters at hand more quickly and not to have to search for them, and to save space. The bag is of high quality and fits perfectly for 100x100mm filters. A total of three (theoretically four) different filters can be stowed in it. So it is perfect for a standard ND filter set (8,64,1000). The inside of the bag is completely lined with microfiber so that the filters can be transported in it without additional protection. As a smart feature, it has a pull-out mechanism. This means that when you open the bag and pull the tab, all the filters are offset and highlighted so that you can grab them much better and read the label directly. I bought another glass filter at the same time - ND64. Since I already own an ND8 from another brand and the ND1000 from K&F, this was of course still missing in the series. Overall, I am super satisfied with the quality of K&F. The filters (update 2020) have almost no color cast anymore. In certain light situations, my ND64 filter turns green. However, this can be corrected without major problems during image processing. The shape of the filter (no round filter) also means that there are no problems with vignetting or falling sharpness. The images are therefore almost unaffected in terms of image quality. The processing is top (no sharp edges, stains, etc.) and the price speaks for itself. All in all, I'm very happy with the entire filter system from K&F and will probably get hold of the gradient filters soon!